"Feser... has the rare and enviable gift of making philosophical argument compulsively readable" Sir Anthony Kenny, Times Literary Supplement

Selected for the First Things list of the 50 Best Blogs of 2010 (November 19, 2010)

Thursday, May 26, 2016

Self-defeating claims and the tu quoque fallacy

Some
philosophical claims are, or at least seem to be, self-defeating. For example, an eliminative materialist who
asserts that there is no such thing as meaning or semantic content is implying
thereby that his own assertion has no meaning or semantic content. But an utterance can be true (or false) only if
it has meaning or semantic content.
Hence the eliminative materialist’s assertion entails that it is itself
not true. (I’ve addressed this problem,
and various futile attempts to get around it, many times.) Cognitive relativism is also difficult
to formulate in a way that isn’t self-defeating. I argue in Scholastic
Metaphysics that scientism, and Hume’s Fork, and attempts to deny the
existence of change or to deny the principle of sufficient reason, are also all
self-defeating. This style of criticism
of a position is sometimes called a retorsion
argument.

At a
conference I was at not too long ago, one of the participants suggested that an
appeal to a retorsion argument amounts to a tu
quoque fallacy (or “appeal to
hypocrisy”). A tu quoque fallacy is committed when someone rejects a claim merely because
the person advancing the claim acts in a way that is inconsistent with it. For example, if I try to convince you that it
is not a good idea to drink to excess and you say “But you drink to excess all the time! Therefore I can dismiss what you’re saying,”
you would be committing a tu quoque
fallacy. That someone is a hypocrite
doesn’t show that what he is saying is false.
But don’t retorsion arguments amount to such an appeal to hypocrisy?

No, they don’t. As every logic and critical thinking teacher
knows, one of the problems one encounters in teaching about the logical
fallacies is that students often settle into too crude an understanding of what
a fallacy involves, and thus tend to see fallacies where there are none. Not every use of language which has emotional
connotations amounts to a fallacy of appeal to emotion. Not
every attack on a person amounts to an ad
hominem fallacy. Not every appeal to
authority is a fallacious appeal to
authority. A reductio ad absurdum argument should not be confused with a
slippery slope fallacy. And so on.

In the same
way, by no means does every reference to an opponent’s inconsistency amount to
a tu quoque fallacy. On the contrary, pointing out that a certain
view leads to inconsistency is a standard technique of logical criticism. It is, for example, what a reductio ad absurdum objection involves,
and no one can deny that reductio is
a legitimate mode of argumentation. The
problem with tu quoque arguments isn’t
an appeal to inconsistency as such. The problem is that the specific kind of inconsistency the arguer appeals to is not
relevant to the specific topic at
issue.

So, suppose
I am a drunkard but I tell you that it is bad to be a drunkard, on the basis of
the fact that being a drunkard is undignified, is damaging to one’s health,
prevents one from holding a job and providing for one’s family, etc. My hypocrisy is irrelevant to the truth of the
claim I am making, because the proposition:

(1) Feser is
a drunkard.

is perfectly
compatible, logically speaking, with the proposition:

(2) It is
bad to be a drunkard.

and
perfectly compatible also with the proposition:

(3) Being a
drunkard is undignified, is damaging to one’s health, prevents one from holding
a job and providing for one’s family, etc.

Hence to
reject (2), or to reject the argument from (3) to (2), on the basis of (1), is
unreasonable. But that is exactly what the
person in my example who commits the tu
quoque fallacy does.

A retorsion
argument is not like that at all. Consider
the objection, raised against Eleatic philosophers like Parmenides or Zeno, that
they cannot coherently deny that change occurs.
The idea here is that the Eleatic is committed to the proposition:

(4) There is
no such thing as change.

but at the same
time, carries out an act -- for example, the act of reasoning to that
conclusion from such-and-such premises, where this very act itself involves
change -- which entails the proposition:

(5) There is
such a thing as change.

Now (4) is not logically compatible with (5). What we have here is a “performative
self-contradiction” in the sense that the very act of defending the position entails
the falsity of the position. So, it is
not mere hypocrisy, but rather implicit logical inconsistency, that is
at issue.

Here’s
another way to think about it. Could
being a drunkard still be a bad thing, even if I am in fact a drunkard myself? Of course.
That’s why it is a tu quoque
fallacy to reject my claim that being a drunkard is bad, merely because I am myself
a drunkard. But could change really be
an illusion, if Parmenides is in fact reasoning from the premises of his
argument to the conclusion? No. That’s why it is not a tu quoque fallacy to
reject Parmenides’ denial that change occurs on the basis of the fact that he
has to undergo change himself in the very act of denying it.

Of course,
Parmenides might respond: “Ah, but that assumes that I really am reasoning from premises to conclusion,
and I would deny that I am doing so, precisely because that would be an instance
of change! So, you are begging the
question against me!”

But, first,
even if the critic’s retorsion argument against Parmenides did amount to
begging the question, it still would not amount to a tu quoque fallacy.

And second,
it does not in fact amount to begging
the question. The critic can say to
Parmenides: “Parmenides, you were the
one who presented me with this argument against the reality of change. I merely pointed out that since the rehearsal
of such an argument is itself an instance of change, you are yourself already implicitly
committed to its reality, despite your explicit denial of it. I am pointing out a contradiction in your own position, not bringing in some question-begging
premise from outside it. So, if you want
to rebut my criticism, it is no good for you to accuse me of begging the
question. Rather, you have to show how
you can restate your position in a way that avoids the implicit contradiction.”

Of course,
no such restatement is forthcoming, because the very act of trying to formulate
it would involve Parmenides in exactly the sort of implicit contradiction he
was trying to avoid. But that would be his problem, not his critic’s
problem. (Eliminativism is, of course,
in exactly the same boat -- as I show in some of the posts linked to above --
as are some of the other claims against which retorsion arguments might be
deployed.)

90 comments:

I do not think Parmenides and the eliminativists are in the same position here.

Parmenides can say, "I eternally assert that there is no such thing as change."

You can respond that the assertion is not really eternal. But that is your position, not Parmenides's position.

The eliminativist, on the other hand, is asserting, "No sentence has a meaning, including this one." And likewise, he asserts, "No sentence is true, including this one." That directly implies that he is saying something which is not true. I do not have to get involved and interpret his actions.

In other words, the eliminativist contradicts himself in a way in which Parmenides does not.

I find that we often ignore the responses of skeptics to claims that they are being self-contradictory. Here is one such response from Sextus:

“For concerning all the skeptical utterances [such as “I don’t know anything”] one must assume from the outset that we are not unconditionally committing ourselves to their truth, not least in view of the fact that we say that they abolish themselves, since they are included among the things to which they apply; they are like purgative drugs which not only eliminate the [unhealthy] bodily humors but also drive themselves out along with the humors . . . Further . . . we say [only] what appears to us, and do not pronounce in such a way as to commit ourselves to the nature of the externally existing objects. On this basis, I think, every sophistical trick brought to bear on a skeptical utterance can be thwarted” (Outlines of Pyrrhonism, 1.206-208).

This is Sextus's response to claims that he isn't being consistent. What he says isn't far from saying that a tu quoque fallacy is being used against him. He makes two arguments: (i) that his skeptical claims refute themselves, but still manage to refute all other knowledge in the process, (ii) that none of his claims are about extramental reality, but only about what seems to be right to him - he is clear elsewhere that he allows knowledge of what seems to be the case to us. I think Sextus's arguments ultimately fail, but they still show that skeptics are not immediately defeated by charges that they are being self-refuting.

However, such arguments can't be used by those Feser is attacking, i.e., scientism proponents, since they aren't trying to refute all claims, including their own, but just metaphysical claims etc. Nor can they say they are only taking about what seems to be the case to them, since they are all quite clear they are making statements about a reality external to them. I even think that skeptics do best defending themselves when they deny that even logical inferences are certain (I think Carneades tries to use the Liar's paradox to show logic isn't certain), but obviously this can't be used by the pro-scientism party.

On the other hand, some hypocrisy arguments aren't necessarily bad ones. The deconstructionist who denies that words have any meaning, then orders a pizza over the phone and goes to pick it up, is acting as if he doesn't believe what he is saying.

Here's a thought: though eliminativism is clearly self-refuting, it seems to me that the Defender of Parmenides (DoP) is not defeated quite so quickly. He may say, "Parmenides denies the reality of change, but does not deny we experience illusions of change. The rehearsal of the argument is not in fact an instance of change, but of precisely such an illusion. It therefore does not constitute a counterexample to the claim that there is no change."

Note that what is illusory here is not the truth-claim of the argument. What is illusory is this: that the act of rehearsing argument amounts to "change." So, unlike eliminativism, Parmenides' argument doesn't collapse immediately by contradicting its own truth-claim.

Of course, it is now incumbent upon the DoP to account for the possibility of experiencing the illusion of change – not a easy task! And perhaps demonstrably impossible (what would it mean for an argument to "change one's mind?" What does "experience" mean at all?). But he doesn't seem quite yet to have been defeated...

What are your opinions regarding paraconsistent logic? I've read that the Aristotelian "first principle" is that of the law of noncontradiction, and yet paraconsistent logic (in the version of dialetheism) seems to allow for propositions to run counter to this law of logic. I, personally, would argue that such a position is contradictory and self-refuting, since one cannot logically deny the LNC without affirming it. Yet paraconsistent logic would claim that this is begging the question since it affirms that actual contradictions can actually hold logically. What are your thoughts?

This is interesting because it seems to relate to an entire field of problems in which everything from the liar's paradox, to the claim to know that it can be known that there is a noumenal phenomenal distinction, to B.F. Skinner's assertion of a privilege to declare despite his own ex hypothesei unfittness to do so , to the Churchland's seeming expectation that they be taken as persons rather than bags of chemical reactions, all seem to set up camp.

In the case of the paradox, I personally side with those like Gilson who see it as not much more than a violation of the rules of sensible subject predicate grammar. There is an elision of some kind that is being tolerated when it should not be.

And the problems involving certain sets of sets don't seem to me to be real problems in the first place; but the result of a determination to do something that doesn't have to be said that way. But then I have enough to handle with basic Peano symbolism and maybe I don't grasp the metaphysical significance of the issue.

But still, I would be interested, since Feser has a good familiarity with Russell in his background, to know if he sees the ramified theory of types as shedding any light on the ability to sometimes make seemingly self-defeating claims. Or is this just a way of stipulating yourself out of trouble ...

I know that that's the old logic, but, nonetheless.

Oh and the dismissive remarks about Internet Geekling's use of "ad hom" and "appeal to authority" etc., gets 5 stars.

What is illusory is this: that the act of rehearsing argument amounts to "change." So, unlike eliminativism, Parmenides' argument doesn't collapse immediately by contradicting its own truth-claim.

Of course, it is now incumbent upon the DoP to account for the possibility of experiencing the illusion of change – not a easy task!

@Erich: I suppose I would have to ask you for further clarification. Are you saying (on behalf of DoP, of course) something like (A) "the seeming act of rehearsing the argument is only a seeming, there is no actual rehearsing the argument", or (B) "there is indeed a real 'rehearsing the argument' but the act of rehearsing the argument is not change"?

The latter would be an uphill claim to defend, for ANY action of any sort at all is change in some sense, and B seems to admit of action. I for one would argue that B simply lets in by the back door what P tries to deny.

As for A, it allows one to simply ignore P's argument: "I have held that there is change, and nobody has presented a counterargument. The seeming acts of counterarguments are illusory, so my argument stands." It appears to be susceptible to all of the problems of lived inconsistency that Prof. Feser outlines above: nobody who argues for P's position actually acts as if they think P's thesis is TRUE, they act as if they believed in change, by acting as if the act of presenting a counterargument is not an illusory sort of thing.

That is a pleasing formulation. And if someone were energetic, they could probably create an entire constellation or even hierarchy of descriptive formulations related to various aspects of problems at least loosely related to the more narrowly defined "recursion" conception; be they purely logical, philosophically, or acidic-ally redounding in an ideologically foundational sense.

@Tony – yes, Mr. PoB would have to defend something closer to B; you're quite right about A, and A goes nowhere for the reason you describe.

But B is still oddly slippery. "Rehearsing an argument," if there really is no change, has to be understood in some other sense than involving change – as does practically everything, of course, in completely non-intuitive ways to boot. But there's certainly nothing special about rehearsing an argument from that point of view; watching anything "happen" at all is but an illusion of change. So rehearsing the argument itself is not a counterexample to the claim that there is no change; it is only yet another example of the illusion of change.

Given the fact that I don't think we can possibly describe the world without slipping in change through the back door, I agree the DoP faces an uphill battle here.

But imagine we are convinced by Parmenides' original argument that there is no change, and Aristotle hadn't come along to offer a simple way out. We wouldn't say the argument was refuted by its own rehearsal (even Aristotle didn't refute it that way). We would just be sitting here with this completely counterintuitive idea that everything we thought was change was really an illusion. Might we have been able to think that through?

Worse yet, we might ask what could possibly constitute a counterexample to such a worldview. For every time a critic claimed, "Aha! You're sneaking the metaphysical reality of 'change' back in here after all!" we cultish DoP's would merely reply, "Ah, but that too must be an illusion, for we have proven change must be an illusion – so you simply haven't dug deep enough!"

It seems the sort of position that counterexamples might not be able to refute. It either fails internally, or more useful and intuitive proposals (such as A-T) overtake it (which is what actually happened).

A man could still truly believe that faithful marriage is better than promiscuity, even if he's still catting around, just like a person can believe that it is better to eat less sugar, even if they are always eating dessert. We all understand that sugar and promiscuous sex have an immediate appeal that can be hard to resist, even if you realize their harm. So, we often think of someone in this situation as weak, unable to achieve the good, not someone who necessarily doesn't believe what he says.

But for someone to say that they don't believe words have meaning and then order pizza over the phone really does indicate that they don't believe what they say. You can't assert that you were irresistibly tempted to believe that words had meaning. If you go to pick up the pizza, it's because you really do expect the pizza to be there. When you order the pizza, you expect people to know what you mean.

Per comment 1, if Parmenides suggested that he is eternally asserting that there is no such thing as change, then he is no longer giving us a reason to accept his claim. He is asserting it, he is not arguing it. Since he's just asserting it, he is not providing us with any motivation, rational or otherwise, to accept it.

However, it remains the case that Parmenides is arguing for his position. Insofar as he is, his claim is self-defeating. So he is either giving us no reason or motive to accept his claim or he is presupposing his claim is false in order to argue that his claim is true.

But for someone to say that they don't believe words have meaning and then order pizza over the phone really does indicate that they don't believe what they say. You can't assert that you were irresistibly tempted to believe that words had meaning. If you go to pick up the pizza, it's because you really do expect the pizza to be there. When you order the pizza, you expect people to know what you mean.

This is true, but I think there is a difference about what oneself believes and what actually makes the position self-defeating. This person's behaviour only shows he himself doen't fully believe his argument, rather than the argument itself is self-defeating.

However, if that person is making an argument that words don't have meaning, that seems different. Here the person is relying on words having meaning to argue they don't, which seems at least close to self-defeating.

@Jim S – Not sure what you're referring to as "comment 1" – but Parmenides certainly did have an argument that change is not possible; he did not simply assert it. It is a very interesting argument, one that Aristotle saw fit to contend with it. Who knows whether he really believed it, or whether he saw it as a thought-experiment to force philosophical thinking of the time to contend with its own limits.

It's flawed for various reasons, and there are far superior ways of thinking about the problem (to wit: Aristotle). But it seems also not as immediately self-refuting as Feser makes it out to be (here and in his other writings). It is self-refuting if the argument itself demonstrates the reality of change. Well, we think that it does – but the argument calls that very intuition into question. So it's not quite so simple.

This post might not be the perfect place for it, but I've been thinking a lot about PSR lately.

I find Dr. Feser's retorsion argument to be intuitively appealing. It seems to me to be sensical that, if PSR is false, there might be no reason whatsoever for our beliefs, rational inferences, etc. to be correct or even probable. I think this makes for a good "skeptical threat" sort of argument-- unless I'm misunderstanding and it's more of a "best explanation" argument, similar to how Victor Reppert treats the argument from reason as a best explanation argument.

That said, was there ever any response to Dr. Parsons' argument that even if we accept PSR it does nothing to remove the skeptical threat?

In short, Parsons says:

"My first response will be a tu quoque: Affirming the PSR provides no protection at all against universal skepticism. It is one thing to think that things have sufficient reasons; it is something else entirely to say that we are in the epistemological position to discover them. We might go wrong every time we think that we have found the sufficient reason for anything."

I realize by the rules of their debate Parsons had the last word, but I'm curious what the response would be to this challenge and I've been unable to find a response in other blog posts.

Affirming the PSR provides no protection at all against universal skepticism.

I don't understand how one would simultaneously affirm a PSR and universal skepticism; if one is a universal skeptic, on what grounds could one conceivably at the same time be affirming even a weak version of PSR, without contradicting oneself? And the fact that we can go wrong, and that this must have a reason adequate to explain it, is precisely why everyone's standard (and definitely not universal-skeptic) approach to establishing things is to rule out possible causes of error. Even going no further than establishing the rationality of that is not a minor advance.

On the other hand, if the point is simply that PSR on its own doesn't tell us about what humans actually know, this is obviously but irrelevant. The error in the argument then seems to come from assuming that "If PSR is false, we're left with universal skepticism" means that "PSR is all that's needed to eliminate universal skepticism", which is obviously false. This is not a tu quoque at all: If I argue against you that you are committed to universal skepticism for rejecting A, to say that even with A universal skepticism still could be true (1) fails to put into question at all my argument against you; (2) still leaves me in a better position than you are in; (3) is entirely consistent with A being simply a necessary condition rather than a sufficient condition for rejecting universal skepticism.

Has anyone cataloged the assumptions required to carry out any logical argument?

If would seem that if a thorough and accurate list could be compiled then any philosophical statement that denied one or more of those assumptions could be countered with the same argument that Feser uses against eliminative materialism.

How much philosophical dreck could be scraped off the hull of modern philosophy if such an effort were undertaken?

I don't understand how one would simultaneously affirm a PSR and universal skepticism; if one is a universal skeptic, on what grounds could one conceivably at the same time be affirming even a weak version of PSR, without contradicting oneself?

It seems to me that Parsons is thinking even if PSR is true, the fact that all our beliefs, rational inferences, etc. have reasons says nothing at all about whether any of those reasons are good reasons. So PSR could be true and we could still be incorrect about everything-- despite the fact that we could have some kind of reasons for everything. Parsons gives the "evil demon" example as an illustration.

I guess I'm thinking Parsons is asking what the PSR-skeptic gains by affirming PSR. For-- according to Parsons-- universal skepticism is a possibility whether or not we affirm it.

It seems to me that Parsons is thinking even if PSR is true, the fact that all our beliefs, rational inferences, etc. have reasons says nothing at all about whether any of those reasons are good reasons

This conflates two different senses of reasons -- to talk of 'good reasons' is to talk of whether one's reasons for saying or judging such-and-such actually support such-and-such. But PSR is not using reasons in this sense but in the sense of actual explanation; the claim Parsons is arguing against is not that beliefs, etc., have reasons in the first sense, but the claim that using them in reason requires taking something like the PSR to be true about whatever those beliefs, etc., are about.

I guess I'm thinking Parsons is asking what the PSR-skeptic gains by affirming PSR. For-- according to Parsons-- universal skepticism is a possibility whether or not we affirm it.

But again, the argument to which he is responding is that universal skepticism seems to be a necessary result of rejecting the PSR; merely responding that universal skepticism might still be possible if one accepted doesn't introduce any kind of symmetry between the two sides at all. And, indeed, it makes obvious what the PSR skeptic gains: moving universal skepticism from already being a necessary commitment to one that still might possibly be avoided, if certain additional steps can be added.

This conflates two different senses of reasons -- to talk of 'good reasons' is to talk of whether one's reasons for saying or judging such-and-such actually support such-and-such.

You misunderstand me-- though it's probably my fault for not stating the thought clearly. PSR can be true such that we have a reason for all our beliefs-- in the sense that they are all caused by an evil demon, brain in a vat, etc.-- but this doesn't seem to remove the threat of skepticism. In other words it does not seem that the fact our cognitive faculties have reasons for their existence at all implies they are accurate, or even makes it more probable that they are accurate.

And, indeed, it makes obvious what the PSR skeptic gains: moving universal skepticism from already being a necessary commitment to one that still might possibly be avoided, if certain additional steps can be added.

I don't see why the PSR-skeptic cannot say universal skepticism is no more a necessary commitment when denying PSR as it is when affirming PSR. For in either case it remains a logical possibility. What is it about the acceptance of PSR that reduces the probability of universal skepticism, then? For as I explained above, affirming that our cognitive faculties have reasons or explanations for their being being the way they are doesn't seem to have any implication for their correspondence to reality whatsoever (e.g. the evil demon or brain in a vat scenarios).

I think PSR is true-- it's almost self-evident in my opinion and seems well-supported inductively-- but I'm left wondering if the retorsion argument works.

In other words it does not seem that the fact our cognitive faculties have reasons for their existence at all implies they are accurate, or even makes it more probable that they are accurate.

But this is extremely obvious given the fact that cognitive faculties can err, and no one, as far as I can see, is claiming that the fact that our cognitive faculties are explicable implies, entirely on its own, that they are accurate. It just doesn't seem relevant; and it certainly doesn't establish that the bare possibility of universal skepticism is as much of a problem as the guarantee of it.

In the scenario being considered, PSR is being granted as true and accepted as true. (If this is not done, the argument can't be doing what it is claiming, namely, saying what follows even if the opponent is right.) But if this is the case, we are already guaranteed at least one truth and one point on which our cognitive faculties are accurate, namely, PSR itself. But it is inconsistent with universal skepticism to allow points on which our cognitive faculties are accurate -- otherwise our skepticism couldn't actually be universal. Therefore on the assumption universal skepticism seems already to be rejected.

What is more, no one has claimed that PSR is the only truth establishable by retorsion; if an argument works in one case, it works across the board unless there is a principled reason for its not doing so. Arguments aren't like cabs; you can't get off at just any point, but have to stick with them as far as they actually go. For instance, if we know PSR, we know that PSR is possibly true; and if we know that, we know that some things are possible; and if we know that, combining it with PSR again gives us that there must be things that explain those possibilities. Or, again: if we accept PSR, we know that we can accept claims; which means that we know that there are claims, and that they can be accepted, and that we are the kinds of things that can accept claims. And so forth.

I don't see why the PSR-skeptic cannot say universal skepticism is no more a necessary commitment when denying PSR as it is when affirming PSR. For in either case it remains a logical possibility.

Even assuming that accepting PSR does not of itself imply that we can know at least one truth, I don't understand why you don't regard this as an illogical inference; you can't draw any conclusion about necessity from a bare possibility -- that's trying to pull a strong modality directly out of a weak modality. It's as if I said that since dogs exist, and therefore are possible, and unicorns are also possible, unicorns exist just as dogs do because they are both possible. If the argument Parsons is rejecting works, then the link between PSR-denial and universal skepticism is necessary; all that Parsons establishes, at best, is that PSR-acceptance does not, on its own and adding nothing else, eliminate universal skepticism. These are not symmetrical positions -- on one universal skepticism is guaranteed, and on the other it might not be. And that was precisely the point -- even assuming that Parsons is right, this kind of argument is not a tu quoque and doesn't actually leave the opponent any worse off.

But if this is the case, we are already guaranteed at least one truth and one point on which our cognitive faculties are accurate, namely, PSR itself.

I'm not sure what importance PSR specifically is supposed to have here-- we could run the same argument you're making with, say, the principle of non-contradiction, the cogito, etc.

If the argument Parsons is rejecting works, then the link between PSR-denial and universal skepticism is necessary; all that Parsons establishes, at best, is that PSR-acceptance does not, on its own and adding nothing else, eliminate universal skepticism.

I still don't see why the link would be necessary between PSR-denial and skepticism. When using the retorsion argument, the defender will want to say denying PSR means it's possible that any or all of our beliefs, etc. are without any explanation whatsoever. But this doesn't entail that any of those beliefs actually are without explanation.

Likewise, even if we affirm PSR, and even though all our beliefs, etc. would have explanations for their being and such, it's still the case that it's possible any or all of our beliefs are illusory (e.g. if caused by an evil demon)-- even though it doesn't entail any are actually illusory.

So either way it seems we're left with the logical possibility that all our beliefs are possibly incorrect, whether by means of lacking explanations or by means of deception via a demon (or whatever). But if this is the case, it seems the PSR-skeptic is on even footing with the person affirming PSR, unless some additional argument can be made that PSR increases the probability that our beliefs, etc. are correct.

I'm not sure what importance PSR specifically is supposed to have here-- we could run the same argument you're making with, say, the principle of non-contradiction, the cogito, etc.

Yes; exactly my point is that the structure of the suggested scenario seems to be incoherent in itself.

I still don't see why the link would be necessary between PSR-denial and skepticism. When using the retorsion argument, the defender will want to say denying PSR means it's possible that any or all of our beliefs, etc. are without any explanation whatsoever. But this doesn't entail that any of those beliefs actually are without explanation.

There's no reason why it would have to. PSR-denial and universal skepticism are positions, not states of the world, and precisely the point of the retorsion argument is that the position, PSR-denial, already commits one to the position, universal skepticism. That's necessity. If you don't want to call it necessity, we can call it commitment or requirement, but it's right there in the structure of the argument.

There is no argument on the table for the symmetrical case involving PSR-affirmation; nothing has been done to establish that PSR-affirmation, the position, already commits one to universal skepticism. In fact, it has very clearly been kept at a level far weaker than that: PSR-affirmation does not on its own rule out universal skepticism.

But if we compare the two cases:

PSR-denial on its own commits one to universal skepticism

PSR-affirmation does not on its own rule out universal skepticism

They aren't logically symmetric. If they are both true, then the PSR-denier is committed to being a universal skeptic, no matter what, but this is not at all the case with PSR-affirmer -- it's still entirely open, either way. If you want to avoid universal skepticism, your only option is PSR-affirmation.

You seem to be taking "logical possibility of universal skepticism" as the thing to be avoided. But this is quite clearly not what is on the table -- the retorsion argument is about accepting something that commits one to universal skepticism, and the response lamely does not return in kind but says, "Well, it seems that PSR on its own doesn't commit one to universal skepticism being false." But this is not much of a response -- there was no claim on the opposing side that it did, and the response leaves the retorsion argument exactly where it was without any answer that reduces its force. (Nor is it actually a tu quoque, because there is no 'and you also', because it is not returning to the opponent the opponent's own claim.)

For heaven's sake, the slippery slope isn't a fallacy. I think people from lands that experience ice and snow regularly should be in a situation to know that imagining a slippery slope isn't dangerous is simply false.

Human history is standing testimony that as much as man rebels against his own reason and intellect, he is notwithstanding almost hopelessly inclined to follow through on the implicit consequences of his own beliefs. Hence allowing two men to call themselves married to each other necessitates that you also allow a man into a woman's bathroom. It will also mean pederasty. Some people will claim that I am engaging in a slippery slope fallacy by that last claim; but they also claimed in Canada after gay marriage was passed in Parliament that allowing homosexual marriage wouldn't result in dudes helping themselves to the women's room.

You can read the Nazi party's original platform online. The final solution is miles away from it and so it a totalitarian, Orwellian state. But it is there implicitly through certain errors, such as equivocating the State's interest with the common and greater good.

...what is it about denying PSR that necessarily commits one to skepticism?

Because PSR is a first principle of reason. If you deny PSR you eliminate any grounds for justifying your own beliefs and assertions and simultaneously eliminate any grounds for denying your opponent's beliefs and assertions.

First principles are simple in the philosophical sense. We typically deny them when they are portrayed to us or we understand them as complex, because complexity involves the possibility of error. No on is in error about the first principles, however. The first principles in a sense make plain that we know and what we know if we know at all.

If I understand Aristotle's hylemorphist doctrine as meaning that material forms are separated from matter, then I will deny such a doctrine because they are not separate. Hylemorphism is difficult because it is hard to draw a distinction between a material form's structure, say, and the matter that structure is in, without separating them in thought. This chair I am sitting on doesn't have its chairness or the cause of its chairness separated from it. It is "with it"; that is, in the matter. If I try to convince a student that its chairness is somehow distinct from it in the sense of separate, the student will rightly think I am a windbag or out to lunch.

It seems to me that Anonymous has a valid point here. If I doubt that every belief we entertain has an adequate explanation, that does not commit me to affirming the possibility that every belief we entertain lacks an adequate explanation. All it commits me to is the possibility that some of our beliefs lack an adequate explanation. There's no inconsistency here.

Even if I were to adopt a stronger position, and deny that every belief we entertain has an adequate explanation, all that this would commit me to is the position that some of our beliefs do indeed lack an adequate explanation. That does not commit me to the self-refuting position that my denial of PSR may turn out to lack an adequate explanation. That would only follow if I were affirming that any belief we entertain might turn out to lack an adequate explanation.

It seems to me that Ed is mixing two kinds of possibility in his retorsion argument: epistemic ("for-all-we-know") possibility and metaphysical (real) possibility.

You don't think it's true. You know it's true; and perhaps you are right about the retorsion argument if, as I said, the retorsion argument portrays it as complex or you understand it to do so. We are vehement about the metaphysical exactly because we are thinking about unchanging realities; hence the great divide between scepticism and dogmatism; but if you are a sceptic, then I can force you to become a Platonist, if I know and understand my Plato well.

You've just begged the question by assuming what what I'm asking to be explained.

Since I've already pointed out that I can't make sense of what you are asking, this would not be surprising at all.

So, again, what is it about denying PSR that necessarily commits one to skepticism? Why does the fact that it's merely possible that our beliefs are without explanation entail skepticism at all?

I've already explicitly pointed out that the answer to the second question is that it doesn't; mere possibility on its own doesn't entail anything about truth or necessity. You are the one who keeps insisting on mere possibility; my consistent point has been that mere possibility doesn't get anyone anywhere in this context; that's why Parsons argument doesn't make much sense as a response, for instance.

As to the first question, the entire discussion has been about Parsons's "tu quoque". An argument that is tu quoque, or intended to be such, by the very definition has to assume, for the purposes of argument, that the argument or position to which it is responding is right -- again, only for the purposes of the argument. The argument to which Parsons is responding is a retorsion argument; retorsion arguments work by identifying, or claiming to identify, a practical inconsistency in the position to which they are opposed; they are ways of arguing that a position is untenable and therefore that the opposite position must be held. If the retorsion argument does not in some way establish an inconsistency of some kind, then it fails completely as a retorsion argument. If I say, "English is a useful language," and you reply, "Well, you find English useful," that's obviously not a successful retorsion argument, because all you've done is shown that I am perfectly consistent. But if I say, "English is useless for communicating anything," and you reply, "But you are using English to communicate something," then this is successful retorsion: for my statement to have its intended force, it must be false, and therefore its effectiveness depends on its own falsehood. Without the inconsistency, there is no argument that the position is untenable. If I have a good argument that a position is untenable, then I have, by that very nature, an argument that any tenable position must be different from it.

The two positions on the table are PSR-denial and PSR-affirmation. The retorsion argument is that PSR-denial is untenable because it requires things that amount to universal skepticism. If it does not do this it already fails.

Since an effective tu quoque assumes the point for the sake of argument, Parsons' argument, if it is a tu quoque, has to begin with the assumption, for the sake of argument, that the retorsion argument works; it then, if it were a real tu quoque, would have to apply the same reasoning to the original position. (That's the whole meaning of 'tu quoque': You Too.) But it doesn't. Instead of showing that the same kind of reasoning would get the same result for PSR-affirmation, it switches to talking about how it would be possible to have universal skepticism even given PSR-affirmation. But the retorsion argument against PSR-denial was not that PSR-denial allows the possibility of universal skepticism -- if that's all it did, it would have failed as a retorsion, because bare possibilities on their own don't establish anything.

Thus if you want to put into question the idea, "denying PSR commits one to skepticism", you need to raise criticisms of the retorsion argument itself. As I've noted, Parsons's argument doesn't do so; it changes the subject from commitment to universal skepticism, which is what the retorsion argument is about, to possibility of universal skepticism, which doesn't get anyone anywhere.

You're missing my point. To bring down the scope a bit, I'm an economist, so it's very common for me to think in terms of costs-- more specifically, opportunity costs. Now, presumably, the goal of the PSR retorsion argument is to force the denier to make a choice, i.e. either accept PSR or deny PSR-- but deny it at some significant cost (e.g. "necessitating" skepticism) they will not want to bear.

Parsons is in effect saying-- if I understand him correctly-- that the denial of PSR has no such opportunity cost. In other words, denying PSR entails skepticism with respect to our beliefs no more than affirming it does.

So that's the question: what, exactly, is the cost of denying PSR as compared with affirming it? Since it's possible that our beliefs are entirely wrong whether we affirm it or deny it, what thereby do we lose by denying it? Does it reduce the probability that our beliefs are incorrect? If so, how? If not, it seems there is no cost to denying it.

Retorsion arguments are arguments that the person in question is already assuming, or acting in ways that only make sense if they are assuming, the claim that they are rejecting. It's a matter of inconsistency, usually practical inconsistency. The point of a retorsion argument is not that a position is costly but that it is untenable (at least in the form in which it is being put forward).

In other words, denying PSR entails skepticism with respect to our beliefs no more than affirming it does.

As I have repeatedly pointed out, this not logically possible given the actual set up.

I'm not sure if it will help Anonymous at all, since Brandon seems to have already given a pretty clear answer to the question that Anonymous keeps posing in different forms, but here's an attempt.

Feser's retorsion argument against PSR-denial, as I understand it, maintains that if we deny PSR, then we can have, to quote Feser, "no reason to trust the deliverances of our cognitive faculties, including any grounds we might have for doubting or denying PSR." Now, accepting PSR does not entail all by itself that I have good reason to trust the deliverances of my cognitive faculties; skepticism remains, as Brandon has repeatedly affirmed, a logical possibility even if PSR is true (Brandon has noted that there are difficulties with supposing that universal skepticism is logically consistent with the affirmation of the PSR, but we need not worry about those difficulties; the basic point about the logic of Feser's retorsion argument and the failure of Parsons' response to it is the same whether we think of universal skepticism or near-universal skepticism). But -- and here is the difference that Anonymous keeps looking for -- while affirming the PSR does not entail that (near universal) skepticism is mistaken, it doesn't entail that it's correct, either, whereas denial of the PSR does, according to Feser, guarantee skepticism. Otherwise put, if you deny PSR, then you can have no reason to trust the deliverances of your cognitive faculties, whereas if you affirm PSR, then while it might still turn out that you can have (virtually) no reason to trust (virtually all of) the deliverances of your cognitive faculties, it might not turn out that way, and with the aid of some additional premises you can avoid being logically committed to skepticism.

So, in Anonymous' economic terms, the cost of PSR denial is that you lose any reason whatsoever to trust the deliverances of your cognitive faculties; the gain of affirming PSR is the possibility that you have good reason to trust the deliverances of your cognitive faculties.

To reiterate Brandon's point, the fact that PSR is consistent with our cognitive faculties being completely untrustworthy, and hence that skepticism is logically possible even if PSR is true, does not put PSR-affirmation on the same logical level as PSR-denial, because PSR-affirmation is equally consistent with our having good reasons to trust our cognitive faculties. Parsons seems to be mistakenly supposing that if PSR-affirmation does not render skepticism logically impossible, it is no worse off than PSR-denial. But Feser's whole argument is that skepticism follows necessarily from PSR-denial, and hence that the rejection of skepticism is logically impossible if PSR is false. If, as Anonymous suggests, Parsons is instead arguing that PSR-denial does not entail skepticism, then that's a different story.

To put it in bland economic terms that Anonymous might find more illuminating, suppose you own a car. If you sell that car to me and I turn it into scrap metal, it becomes impossible for you to drive that car. If you do not sell the car, it remains possible for you to drive it. You might not drive it -- perhaps you have another one that you prefer, or you lose your license and decide to obey the law about not driving without one -- but it's still possible for you to drive it. According to Feser, denying the PSR is like selling me your car so I can turn it into scrap metal, while affirming it is like not selling it. If you can't see the difference in terms of opportunity gains and costs, then there's probably nothing anyone here can do for you.

Of course, Feser might be wrong; it may be that denying the PSR does not in fact commit a person to skepticism, because PSR could be false and yet we could still have good reasons to trust our cognitive faculties. But it's one thing to say that his argument is false; it's another thing to say that it treats the logical relationship between skepticism and PSR-denial in the same way that it treats the relationship between skepticism and PSR-affirmation. It doesn't.

Well, please point out to me where you have demonstrated that denying PSR entails a greater degree of skepticism than affirming it does, because I am not aware of any such demonstration.

Well, earlier you seemed to claim that you'd read Feser's retorsion argument against PSR-denial. Are you now denying that you've even read it, or are you simply casting doubt on whether it succeeds in showing that if you deny PSR, you can have no good reason to trust the deliverances of your cognitive faculties? In any case, I think Brandon hasn't "demonstrated" it because the whole conversation has taken Feser's argument in Scholastic Metaphysics as the background. That's the argument. Go read it.

Well, please point out to me where you have demonstrated that denying PSR entails a greater degree of skepticism than affirming it does, because I am not aware of any such demonstration.

This is not the relevant point; we are not talking about PSR in general but about the relation between the retorsion argument against PSR-denial and Parsons's purported tu quoque response. The purported tu quoque argument is entirely devoted to claiming that even with PSR-affirmation, universal skepticism still may be possible. This is the set-up.

The question then becomes: Is it possible, given this logical set-up, actually to draw from the purported tu quoque argument the conclusion that denying PSR entails skepticism with respect to our beliefs no more than affirming it does? And as I have pointed out at length over multiple comments, it is not. Retorsion arguments conclude to untenability. The retorsion argument in this case does so by arguing that PSR-denial requires universal skepticism. One could simply reject this argument, but Parsons's response is put forward as a tu quoque argument. Tu quoque arguments, by their nature, have to accept for the sake of argument what they are responding to, because their whole point is to turn it around on the opponent. However, Parsons's response does not actually mirror the retorsion argument to which it is responding. The retorsion argument is to the effect that PSR-denial on its own requires universal skepticism; this is the ground for why PSR-denial is supposed to be untenable. It purports to give (an at-least-practical) necessity. Parsons's response is to the effect that PSR-affirmation does not on its own eliminate universal skepticism. It does not purport to give us any kind of necessity; it gives us, at best, a bare possibility. Nothing whatsoever can be drawn from this alone about the tenability of PSR-affirmation.

If one interprets the argument as saying that "denying PSR entails skepticism with respect to our beliefs no more than affirming it does", this logically requires that the argument tell us that if PSR-denial entails skepticism, PSR-affirmation entails skepticism. This is not logically possible -- the argument does not in any way require us to conclude that PSR-affirmation entails or implies skepticism; Parsons's response, if accepted, only gets one to the conclusion that PSR-affirmation on its own does not entail or imply non-skepticism. As I said at the very beginning: the retorsion argument, if accepted, gives us the result that PSR-denial commits one to universal skepticism. Parsons's response does not give us the result that PSR-affirmation commits one to universal skepticism; it only gets us to the conclusion that ruling out universal skepticism requires more than just PSR-affirmation, and is entirely consistent with PSR-affirmation being a necessary condition for rejecting universal skepticism (which is all the retorsion argument requires in the first place).

` In any case, I think Brandon hasn't "demonstrated" it because the whole conversation has taken Feser's argument in Scholastic Metaphysics as the background. That's the argument. Go read it.

No need to be pedantic. I have a physical copy of the book and I've read it several times. I actually own several of Dr. Feser's books and I've enjoyed all of them. I'd be happy to post a picture of it if you don't believe me. I'm not attacking anyone here and the fact that you seem to think otherwise is odd.

Otherwise put, if you deny PSR, then you can have no reason to trust the deliverances of your cognitive faculties, whereas if you affirm PSR, then while it might still turn out that you can have (virtually) no reason to trust (virtually all of) the deliverances of your cognitive faculties, it might not turn out that way, and with the aid of some additional premises you can avoid being logically committed to skepticism.

This is more of the type of answer I'm looking for, which is why I had to state the question ad nauseam with Brandon, who very clearly did not answer it and kept missing the point.

To quote from the book:

But if PSR is false, we could have no reason for thinking that any of this is really the case. For all we know, what moves or causes us to assent to a claim might have absolutely nothing to do with the deliverances of our cognitive faculties, and our cognitive faculties themselves might in turn have the deliverances they do in a way that has nothing to do with truth or standards of logic. We might believe what we do for no reason whatsoever, and yet it might also falsely seem, once again for no reason whatsoever, that we do believe what we do on good rational grounds. Now this would apply to any grounds we might have for doubting PSR as much as it does to any other conclusion we might draw.

To me, nothing in this precludes our faculties being accurate even if PSR is false; PSR could be false and yet it's still possible all of our faculties are accurate. Or they might all be incorrect. Likewise if we affirm PSR.

If I'm missing something (i.e., how PSR does preclude the accuracy of our faculties), then I would like to be corrected.

To me, nothing in this precludes our faculties being accurate even if PSR is false; PSR could be false and yet it's still possible all of our faculties are accurate. Or they might all be incorrect. Likewise if we affirm PSR.

Since the position of universal skepticism itself doesn't preclude our faculties actually being accurate, this is irrelevant to both the retorsion argument and the purported tu quoque response. As I already pointed out.

As I explicitly made very clear that I didn't understand your question, perhaps you should perhaps complain about your own stupidity in simply repeating it ad nauseam while getting the same result.

Very odd to resort to name calling when all I'm doing is asking for an explanation and then point out that you did not understand the question. All I did was agree with you-- you admitted you did not understand the question!

You say:

And as I have pointed out at length over multiple comments, it is not. Retorsion arguments conclude to untenability. The retorsion argument in this case does so by arguing that PSR-denial requires universal skepticism.

This is what I'm asking for a demonstration: how do we get from the fact that denying PSR means our faculties might be with no explanation-- which I wholeheartedly agree with-- to the claim you're wanting to make, i.e. PSR denial requires universal skepticism?

No, you said that you repeated a question ad nauseam to someone who did not understand the question despite recognizing that they didn't.

how do we get from the fact that denying PSR means our faculties might be with no explanation-- which I wholeheartedly agree with-- to the claim you're wanting to make, i.e. PSR denial requires universal skepticism

(1) This is not what you were asking a demonstration for, since this is a question about the success of the retorsion argument. You explicitly asked about the purported tu quoque argument; as I pointed out, the purported tu quoque argument has to assume for the sake of argument that the retorsion argument does succeed in showing that PSR-denial requires universal skepticism. If the retorsion argument does not succeed in showing that PSR-denial requires universal skepticism, the tu quoque argument is otiose and irrelevant.

(2) The retorsion argument doesn't argue that denying PSR means our faculties might be with no explanation; denying or affirming a position doesn't tell us anything about whether our faculties have no explanation, because the denial or affirmation might itself be wrong. It argues that denying PSR is practically inconsistent with trusting one's faculties (to use the terms in which Retorsion Retort quite rightly put it). It does that by retorsion (hence the name): in denying PSR, PSR-deniers are engaging in practices that involving acting in ways that only make sense if they are trusting their faculties. Thus the practical inconsistency.

It argues that denying PSR is practically inconsistent with trusting one's faculties (to use the terms in which Retorsion Retort quite rightly put it). It does that by retorsion (hence the name): in denying PSR, PSR-deniers are engaging in practices that involving acting in ways that only make sense if they are trusting their faculties. Thus the practical inconsistency.

I understand this.

What I'm asking is what, exactly, is the inconsistency?

I do not see any explicit inconsistency between:

1) I trust my faculties.

and

2) It's possible that at least some things are as they are with no explanation whatsoever.

It does that by retorsion (hence the name): in denying PSR, PSR-deniers are engaging in practices that involving acting in ways that only make sense if they are trusting their faculties, which requires assuming that the results of those faculties have identifiable sufficient reasons. Thus the practical inconsistency.

2) It's possible that at least some things are as they are with no explanation whatsoever.

(1) Your (2) is consistent with affirming PSR as certainly true for a limited domain. If the question is not whether PSR should be affirmed but only whether we should affirm it for a larger or smaller domain, the discussion ends up being very different. (Also one to which the purported tu quoque argument is completely irrelevant, though.)

(2) Trusting one's faculties requires assuming there are sufficient reasons for their results. Denying the PSR eliminates the guarantee that they are.

If one holds that PSR can be affirmed for the limited domain of our faculties but not necessarily for anything else (I've never come across anyone giving this position, but given the ambiguity of your (2), I include it in case it is what you are thinking), one would need a principled reason for drawing the line like that. There doesn't seem to be one, because any such reason would seem to require that PSR be more general than the domain to which one is trying to confine it.

I don't think anything I've said goes beyond what Brandon had already said. I also don't think what he said was any less clear than what I said. I just thought that perhaps it was less clear to you given the particular assumptions and terms you were bringing to the discussion (which is not as such an insult to you, since we all come at these things from a particular perspective that involves less than perfect understanding of everything). As for pedantry, I apologize, but you have been so frequently unclear and so frequently misunderstood what seemed to be fairly clear that it seemed appropriate to ask whether you had actually read the book and to point out that the book contains what you were claiming you hadn't seen.

But just in case Brandon continues to make less sense to you than I do, here's an additional point. The recursion argument as such does not purport to show that if PSR is false, our cognitive capacities are untrustworthy. What it purports to show is that we cannot reasonably take ourselves to have good reason to trust those cognitive capacities if we deny the PSR. So the thought is not that if PSR is false, skepticism is necessarily true; it is that the denial of PSR is inconsistent with the rejection of skepticism.

Given this feature of the argument, I can see why you might sensibly have thought that skepticism is no more or less likely given the denial of PSR than its affirmation. It's just that the retorsion argument doesn't purport to claim otherwise. What it purports to show is that if you reject PSR, you cannot even in principle have any reason to reject skepticism. But of course you could have no reason even in principle to reject skepticism even if skepticism (qua the thesis that our cognitive capacities are not trustworthy) is false. That'd be a pretty odd conclusion, but it's not obviously incoherent; some people read Hume as having held something like this, viz. that while reason gives us no resources to reject skepticism, our cognitive capacities are in fact for the most part basically reliable because they've developed over time in conditions such that we wouldn't have survived if they weren't. That may be a mistaken reading of Hume, and it may be ultimately untenable (one wonders how we're supposed to know all that stuff about reliable capacities and habits developing over time if we have no rational resources for resisting skepticism, but hey). But in any case, the retorsion argument makes a claim about what a person can consistently affirm and deny and claim to know or believe with rational justification, not about what can and can't be true.

If you find that a weakness of the retorsion argument, you're not alone. I find retorsion arguments unsatisfying for precisely this reason. Even when I'm convinced that they go through on their own terms (and I'm not perfectly convinced of that, either with Feser's retorsion argument for PSR or with similar arguments for the rejection of determinism, though I find them mostly convincing), it's less satisfying to be shown that I can't help but think P without falling into inconsistency than it would be to be shown that P must be true, since of course there might be some things that I can't help but think without falling into inconsistency that are nonetheless not true. Admittedly, "I can't coherently deny P, but P might still be false" does not inspire much worry that P might still be false. But it does put some pressure on the idea that I can claim to know that P is true; after all, Kant insisted that we can't coherently deny free will, but he also insisted that we can't justifiably claim to know that we really are free. But even if I'm right to be unsatisfied with retorsion arguments and the like, that'd only be a problem if they were the only arguments for things like affirming PSR, rejecting determinism, etc.

Brandon, you say that you've never come across anyone who holds that PSR can be affirmed for the limited domain of our faculties but not necessarily for anything else. But what about the related but different claim that while PSR can be affirmed for many domains, it can't be affirmed for all? It would be strange to hold PSR for our cognitive faculties but nothing else, but it doesn't seem so strange to hold that PSR is not exceptionlessly true in every domain. This, it seems, is where one might find some traction in resisting retorsion arguments for PSR, or PNC, or what not. Granted that we cannot claim that PSR and PNC are generally false without falling to the retorsion arguments, why suppose that we fall to the retorsion argument if we allow that there might be some exceptions to these principles in special cases (quantum physics, weird logical puzzles, whatever)?

In other words, do you think the retorsion argument shows that PSR (or PNC, or whatever) must be exceptionlessly true? And if so, does this have anything to do with special features of the PSR as opposed to PNC? I don't mean to endorse this sort of challenge to the argument, I'm just genuinely puzzled because metaphysics isn't exactly my strong point.

This, it seems, is where one might find some traction in resisting retorsion arguments for PSR, or PNC, or what not. Granted that we cannot claim that PSR and PNC are generally false without falling to the retorsion arguments, why suppose that we fall to the retorsion argument if we allow that there might be some exceptions to these principles in special cases (quantum physics, weird logical puzzles, whatever)?

This is essentially what I'm asking.

I agree with Brandon that, if one wants to affirm PSR in some instances and not others, there would need to be a principle reason for doing so (similar to the paper Dr. Feser posted a while back from Michael Della Rocca).

But I'm not seeing an obvious inconsistency between admitting PSR could be false for some things, and still trusting our faculties.

Again I apologize to Brandon and anyone else if my posts came off as hostile. It was 100% my mistake for not stating my question more clearly.

I suppose in a way it's very much like the claim that the principle of causation only applies to phenomena. You get some oddities with such claims from the fact that you'd need an explanation that shows that your causal explanations only extend over such-and-such domains, and it's not always easy to determine how that works. It gets even more ticklish with the PSR, since the PSR, depending on exactly the version one uses, is arguably even more general. That gets very complicated very quickly, although complicatedness is a different issue from self-defeat.

As to retorsion arguments, I think such arguments can indeed be sensitive to adjustments of domain. This is because adjusting the domain can change the actual position, and retorsion arguments need to latch on to some feature of that particular position. To show that a position is self-defeating, you need to start with the position itself. This raises the possibility that you could have a denial of PSR for such-and-such domain that is not self-defeating because the domain has nothing whatsoever to do with putting the position itself forward. Denying PSR for reasoning and communication raises immediate worries about self-defeat, because PSR-denial in practice involves reasoning and communication. But denying PSR for ducks, and only ducks, while bizarre and in need of explanation, might not involve self-defeat at all, since PSR-denial, in itself, doesn't seem to have anything to do with ducks.

Well, I'm not confident about this (which is why I asked Brandon), but the two thoughts I have about it are (1) that the fact that we would need a reason for drawing exceptions might entail that they're not genuine exceptions, and (2) drawing exceptions in special, limited domains is not quite the same as rejecting the principle. If I reject a principle, then I can't reasonably operate with the presumption that it generally holds good until there are found to be good reasons for drawing an exception; but the fact that a principle does or might have some exceptions does not make it unreasonable for me to operate on the presumption that it generally holds good. We do this a lot with practical principles. It is the apparently fundamental character of PSR and its special features that make me doubt whether this would be a tenable line to take in this case.

At least if we're talking about existence, I think Feser's post on Della Rocca's article gives some good reasons to think that we're committed to PSR provided that we think the existence of anything can be explained.

The Della Rocca argument may indeed be a good one. But that's a separate argument.

I think despite all the misunderstandings, "Anonymous @ 6:03" may have a point:

I don't see why they couldn't hold the beliefs that "there might be things that exist with no explanations whatsoever" and "my faculties are probably accurate" concurrently.

After all, the person denying PSR probably isn't making the claim that there are no explanations for anything. Instead they're making the much weaker claim that it might be the case that not everything has an explanation. And it's not clear that this would be inconsistent with thinking there is an explanation for our cognitive faculties.

This is true, but I think there is a difference about what oneself believes and what actually makes the position self-defeating. This person's behaviour only shows he himself doen't fully believe his argument, rather than the argument itself is self-defeating.

However, if that person is making an argument that words don't have meaning, that seems different. Here the person is relying on words having meaning to argue they don't, which seems at least close to self-defeating.

Agreed that there are two different arguments against deconstruction here:

1. Because of how they use words, nobody actually believes that words have no meaning.2. Arguing that words have no meaning using words is self-defeating.

Argument 2 has been used against deconstruction. However, I would say that argument 1, while it does not show that deconstruction is self defeating, is still a good argument.

Connor, you might want to go re-read the Della Rocca argument. It is in fact directed against precisely the sort of move you sketch here, i.e., that some things are explicable but others are not. It's of course true that Della Rocca's argument is not exactly a retorsion argument, let alone the one that Feser makes. But one might reasonably regard it as (a version of) a supplementary argument to show that the selective acceptance of explicability is not a viable alternative.

I literally read it (and Feser's explanation of it) after seeing your link and before making my above post. So I understand perfectly well that it is a solid argument against the individual that wants to claim explicability arguments are legitimate in some instances and not in others (like PSR).

That said, I'm not sure we would want the retorsion argument to rely on an additional argument to go through. Suppose, for the sake of argument, Della Rocca's argument doesn't work for whatever reason. Does this then mean the retorsion argument doesn't work either (because no inconsistency between holding some things can be without explanations and trusting our faculties)?

But I'm not seeing an obvious inconsistency between admitting PSR could be false for some things, and still trusting our faculties.

I'm not sure, but don't sceptical arguments generally claim only the possibility that are we mistaken is enough? It is not claimed we are necessarily a brain in a jar, but that we could be. Here, presumably, the point is that simply not knowing that when we conclude that we belief something for a reason we might actually believe it for no reason is enough to lead to scepticism.

"The recursion argument as such does not purport to show that if PSR is false, our cognitive capacities are untrustworthy. What it purports to show is that we cannot reasonably take ourselves to have good reason to trust those cognitive capacities if we deny the PSR."

I can think of one good reason: survival. Our cognitive capacities must be reliable enough to have enabled us to survive as a species, for hundreds of thousands of years. Hence on a pragmatic level, at least, they must work.

I would agree, of course, that someone who doubts PSR has no special reason to believe that the theoretical explanations (or models) which scientists come up with are actually true. But I think that a PSR-skeptic could bite the bullet and accept that. He might say that our models "work" in the sense that they yield correct predictions, while conceding that any of these models could be overturned tomorrow.

By contrast, Della Rocca's argument, in a nutshell, is that "we can have no good reason to think anything is explicable unless we also admit that everything is." In other words, it is arbitrary to allow some kinds of explicability arguments, while denying others. But it seems to me that a PSR-skeptic could consistently argue that while many states of affairs (including the existence of objects) do in fact have an explanation, there's no reason why they must do so.

To sum up: while I find PSR immensely plausible, I'm not sure that its denial is logically incoherent.

I'm not sure, but don't sceptical arguments generally claim only the possibility that are we mistaken is enough?

I don't see why it would be. I believe this was why Anonymous above mentioned costs. If denying PSR merely means it is possible that we are mistaken, this would be no more of a threat to the PSR skeptic than would be the possibility that we are deceived by Descartes' demon.

So, if there is no strict inconsistency between saying PSR could be wrong and believing one's faculties to be accurate, it does not make for a very strong skeptical threat argument.

Vincent, I would encourage you to read this book http://cosmicfingerprints.com/evolution/ . I also suggest http://mattfradd.com/how-to-win-an-argument-without-losing-a-soul/ based on prior discussions. Peace.

Our cognitive capacities must be reliable enough to have enabled us to survive as a species, for hundreds of thousands of years. Hence on a pragmatic level, at least, they must work.

They don't need to be reliable in any truth-tracking sense. Meaningful cognitive capabilities, full stop, aren't necessary for some things to survive a very long time, in principle. And why would we be talking about species and survival again? Those are more models we have no right to regard as true.

But I think that a PSR-skeptic could bite the bullet and accept that. He might say that our models "work" in the sense that they yield correct predictions, while conceding that any of these models could be overturned tomorrow.

It isn't about whether or not the models could be overturned. It's about whether they meaningfully reflect reality at all, regardless of whether or not they're overturned. The models may stick around for ages, and still be wrong. The models we replace them with, also wrong.

I think what's confusing people here is that they recognize that in a world where the PSR does not hold, it can still be the case that X is caused by Y, and then reason that if someone believes that X is caused by Y, their belief is true, so surely everything is okay. Except the live possibility that Y is not caused by X, and that Y doesn't in fact need a cause at all, or that Y can be caused by X once but not necessarily again, and so on, and so on... wreaks havoc.

Sure, you can go ahead and make a faith claim: 'I believe that Y is caused by X, and that's that.' Fideists can still exist in the PSR-free world. I don't think the anti-PSR proponents will like that solution.

Connor,

If denying PSR merely means it is possible that we are mistaken, this would be no more of a threat to the PSR skeptic than would be the possibility that we are deceived by Descartes' demon.

I'm not sure "Possible we are mistaken" accurately sums things up. It seems more that we're undercutting the possibility of having a good reason to believe our views are accurate. Again, fideism is an option. But victory, that is not.

I'm not sure "Possible we are mistaken" accurately sums things up. It seems more that we're undercutting the possibility of having a good reason to believe our views are accurate. Again, fideism is an option. But victory, that is not.

I think the most pressing point is that, for the retorsion argument to work, there must be some inconsistency between concurrently holding the following propositions:

A) It could be the case the some things exist with no explanation whatsoever.

and B) My cognitive faculties track truth and standards of logic.

I see no explicit inconsistency between holding A and B. So is there an implicit inconsistency? If so, what exactly is it?

My point, though, is that something about B must implicitly commit us the truth of PSR (which would then make B incompatible with A) so the retorsion argument would work. So what is it about B that commits us to PSR? I'm not saying there isn't a reason trusting our faculties must commit us to PSR, but I do not see an obvious reason for that to be the case.

One thing I've been considering is what would happen if the person denying PSR wants to say their cognitive faculties have reasons but other things necessarily do not. It seems they would owe an explanation for why this is the case. But then any purported explanation would seem to beg the question, as it would implicitly assume the reliability of the very faculties being called into question by their own denial of PSR. If that makes sense.

The reason I'm zeroing in on the 'could be' here is that I think that's tripping up the analysis. A doesn't assert, it's entertaining as a possibility with who-knows-what parameters in play. I think even Ed Feser himself, in some sense, will say 'It could be the case that some things exist/some events take place with no explanation whatsoever.' Not because he affirms brute facts, or even thinks they're possible, but in a more circuitous sense of being willing to entertain an argument that purports to establish said possibility. That's not enough to be interesting.

Either way, the 'could be' gets imported into B. Insofar as it's regarded as possible that any things lack explanations, all things possibly lack explanations, including my own thoughts. For my cognitive faculties to track truth and logic, certain things must obtain. The conclusions I draw need an explanation, and so on. Insofar as those are in doubt, my mind is in doubt. And if anything can lack an explanation, my mental faculties are up for grabs.

I think you're getting that with your latest example. 'My cognitive faculties have reasons/explanations but other things may not'. Okay. Why are they protected? It turns out there's no explanation for that. Explanations are what we're doing away with, after all. That undermines their confidence in their mental faculties.

I'm thinking that, if PSR is false, there is no a priori reason to hold that are faculties are either likely or unlikely to have an explanation. If that's the case, it seems we can put something like a ~.5 probability on our faculties having an explanation (I hesitate to put a number on it, but I'm just doing so to illustrate my thoughts). But that, surely, is not enough to ward off skepticism or justify us in assuming our faculties to be relaible. Do you agree, or am I way off base?

Or is your point that many people accept the possibility of deception by the Cartesian demon and shrug it off, without even trying to refute it, and the PSR sceptic can do the same?

This is true. There is difference, as the PSR sceptic is putting forward an argument that seems to open up a new manner of scepticism for him to fall into. You could say that this is a good reason not to follow him.

@ Edward Feser: The critic can say to Parmenides: “Parmenides, you were the one who presented me with this argument against the reality of change. I merely pointed out that since the rehearsal of such an argument is itself an instance of change, you are yourself already implicitly committed to its reality, despite your explicit denial of it. [...]"

Maybe it's helpful to distinguish a few ways in which Parmenides could be said to be "already implicitly committed to [change's] reality". I think that people get confused by retorsion arguments because they misunderstand what you mean by "implicitly committed". Indeed, consider the following three distinct interpretations:

Claim (1): One of the implicit premises of Parmenides's argument is that change does exists. That is, any adequate formalization of Parmenides's argument would have to include change as an explicit premise.

Claim (2): By making his argument, Parmenides is in fact causing change. In particular, your mind goes through the process of considering each inference in succession.

Claim (3): Parmenides is motivated to make his argument by an implicit belief that the argument will cause change in your mind. (Of course, this implicit belief might be unknown even to him.)

I think that many people who reject your retorsion argument confuse your argument with either Claim (1) or Claim (2). They then reject your argument because (1) is probably false, and (2), while true, obviously begs the question.

But such rejections are mistakes, because your argument really rests on Claim (3), not (1) or (2). And (3) doesn't beg the question, because it is just the claim that Parmenides has a particular belief, not a claim that a particular change occurred. You're not even asserting that this alleged belief of his is true. Rather, you're just arguing, without assuming the existence of change, that he must believe in change. Your argument is just that his having a belief in change is implied by his choosing to make an argument at all. For, why else would he do that, unless he thought that the argument would cause a change?

Nonetheless, I still think that your retorsion argument fails, even after it is properly understood as a claim about his motivation for making his argument.

To get at why I think that the retorsion argument fails, let me go back to why it would be begging the question to base your argument on Claim (2), i.e., that Parmenides's argument actually causes change.

Claim (2) is true, of course. After all, change really does exist, and arguments really do cause changes. But Parmenides wouldn't see it that way. He would say, That which you call "change in your mind" is really there, but it is not really change. What you're calling "the process of considering each inference in succession" is not really a process. There is no succession. The appearance of succession is an illusion. What is there is just something "X" that is "this way". That's all.

But, as I said, your argument doesn't appeal to Claim (2). It appeals to Claim (3), which asserts that Parmenides is motivated by the desire to bring about a change.

So what's the problem with the argument? Well, first, since this is a claim about his motivations, we are at a disadvantage if he denies the motivation that we ascribe to him. After all, he does have privileged access to his own motivations.

And indeed, in this case, he can say, I am motivated by what you *mistakenly* call a change. My motivation is nothing but that "X" be "this way". That's all. I'm not trying to make this X "change". I am just doing that which must be the case for X to be the way it is.

Perhaps one can justly criticize Parmenides for being obscure about what "X" is if doesn't involve any change at all. But that's different from being able to say that he is "committed to the reality of change".

Consider an analogy: Suppose that we lived in Metropolis. Rumors are flying that this superpowerful being called "Superman" has been seen leaping over tall buildings downtown. Moreover (and contrary to the actual mythos), the rumors say emphatically that this "Superman" is Clark Kent. But Clark Kent himself denies this.

You and I are discussing these rumors. You know that the rumors are true, but I don't believe that Superman exists. I think that the reported sightings are just swamp gas. But I do believe in Clark Kent, because I work with him at the Daily Planet.

Suppose that I make the following argument against the existence of Superman: If Superman existed, then he would be Clark Kent. The rumors are very clear about that. But I know Clark personally, and he has told me many times that he is not Superman. Clark is very trustworthy, so Superman must not exist.

Set aside the quality of my argument. I'm certainly committed to the existence of Clark Kent. My argument makes no sense if I don't believe in Clark Kent. Nonetheless, it's not valid to say that I am "implicitly committed to the reality of Superman". You know that Clark Kent is Superman, but it doesn't matter. Unless I know it too, I'm committed only to Clark Kent, not Superman.

I think that you're doing something similar when you accuse Parmenides of being implicitly committed to the reality of change. He's committed to the reality of something, and we know that that something is change. But he doesn't know that, so he's not committed to the reality of change.

I don't see why we couldn't treat the retorsion argument like-- as Anonymous mentioned above-- a best explanation argument.

It would look something like:

i) If PSR is false, then it is not improbable my cognitive faculties are without reasons.ii) ~(It is not improbable my cognitive faculties are without reasons.)iii) ~(PSR is false).

(i) would seem to be hard to deny, because if PSR is false anything could be without reasons. But in that case, we would have no a priori reason for thinking our faculties are even likely to have reasons for being as they are. It would seem to result in agnosticism w.r.t. our faculties, at best.

(ii) could just be treated as a necessary assumption to engaging in rational inquiry. You could deny it, but it would seem to be incoherent to do so.

I made much the same point (far) above (and was already anticipated by an earlier comment). I think you're quite right. It might be instructive to dig into Parmenides' argument and defend it to the hilt, without making any assumptions of what he meant, and see what happens.

So: P has asserted that change is not real, and he's got some argument X for it. Nothing we call "change" really is so. The blooming of a flower in the garden, the satisfaction of my hunger by a good meal, the apparent change in the position of my hand, the apparent change in someone's opinion – all are illusion.

But from this position it's obvious that P's argument, which Feser says "changes" an opinion, does not change anything. We may think it "changes" peoples' minds, but that's just illusion. Feser offers here no notion of change that is not instantly neutered by Parmenides's criticism.

Of course Feser is ultimately right, and Parmenides wrong – these problems at least can be overcome with Aristotle – but he's doing a disservice to the force of his real arguments by claiming Parmenides undermines himself when he does not.

It seems to me the argument is not very convincing without a careful definition of what is meant by "change". For example, an advocate of the B-theory of time denies the sort of "change" that requires an objective present moment, but they'd still usually accept "change" in the sense that there can be differences between different 3D cross sections of 4D spacetime (in the same way one might speak of the area of a circular cross-section of a cone "changing" at different points along the central axis that goes through the tip). Similarly, there are many who would say there is no temporal "change" in the platonic realm of mathematics, but that doesn't negate the idea that this platonic realm can contain logical proofs which "start" from a series of axioms and proceed via a series of inferences to some proposition that's the conclusion.

About Me

I am a writer and philosopher living in Los Angeles. I teach philosophy at Pasadena City College. My primary academic research interests are in the philosophy of mind, moral and political philosophy, and philosophy of religion. I also write on politics, from a conservative point of view; and on religion, from a traditional Roman Catholic perspective.